Edgars Mall of the South i need my money back.

I am the mother to girls triplets who normally buy clothes at Edgars Mall of the south. I went and bought my clothes and decided to buy 3 dresses for my Triplets. When I get home one of the triplet dress was big and had to return it back. I was never given an original slip the lady who assisted me took my slip and gave me the new slip. It happend that I decided to go and exchange some of my clothes for my babies shoes as they were going for the photoshoot the following day but couldn't get the sizes then I decided to ask for a refund as they took my slip the lady who assisted me says she is going to look for my slip in the office and she came back saying she couldn't find it so they will not assist me. Then I said I need the money because I need to go and buy shoes somewhere and they are refusing and they took my slip. I ended up going to H&M to spend R850 for my babies shoes. Edgars Mall of the south i need my money back. I even showed them the transaction and I request a footage of the day I came to exchange the clothes. They took my slip and now that they misplaced it is now my problem? Why would I **** that what they do.